<template>
  <div>
    <h1>父</h1>
    <div>{{ num }}</div>
    <Son :value="num" @input="val => num =val" />
  </div>
</template>

<script>
import Son from './son.vue'
export default {
  components: {
    Son
  },
  data() {
    return {
      num: 100
    }
  },
  methods: {

  }
}
</script>

<style>

</style>
